Add more butter to skillet if needed. When foaming subsides, add roast, cooking at least 1 1/2 minutes per side, until nicely browned. Place roast on top of vegetables in slow cooker.

Add flour to any juices remaining in skillet. Stir to combine, then deglaze skillet with red wine, whisking if needed, to remove lumps. Whisk in stock, then molasses, tomato paste and cream. Bring to boil then pour over roast and vegetables in slow cooker. Add bay leaf, thyme and rosemary to cooker and push into sauce. Cover cooker with lid and turn to low for 8 hours.

To serve, place roast and all the vegetables onto platter. Pour sauce into saucepan and skim fat from surface. Bring briefly to boil, skim any remaining fat. Taste sauce and adjust seasonings to your liking. Pour sauce into separate pitcher to pass with the meat and vegetables. Serve immediately. (Remove string from roast if any was used to tie roast into shape.)